This invention relates generally to spatial light modulators that may be used, for example, for creating digital displays for electronic devices.
There is an increasing demand for relatively compact digital displays for a wide variety of electronic devices. For example, cellular telephones and a variety of other appliances have a need for a relatively compact display and in some cases the entire device may be sufficiently compact to be handheld. These devices have processor-based systems for running a variety of applications as well as the display. Conventionally a printed circuit board is utilized to organize a variety of integrated circuit chips to implement the processor and the circuitry for the spatial light modulator. This tends to spread the size of the device laterally increasing the minimum possible device size.
A number of emerging display technologies make it possible to provide relatively compact displays. For example, reflective light valves may be based on liquid crystal on silicon (LCOS) technology to merge mature silicon technology with liquid crystal optics technology. Micro displays as are used in handheld mobile phones and rear projection displays for personal computers and home entertainment are applications of hybrid reflective light modulator technology. In addition, grating light valves from Silicon Light Machine and the digital micro-mirror devices (DMMD) from Texas Instruments may also be used to create displays.
A spatial light modulator modulates the optical properties of a medium to allow an image to be displayed when the medium is exposed to light. The nature of the spatial light modulator is essentially inconsistent with the nature of the microprocessor. The microprocessor is an entirely silicon device which may be formed of a die and packaged with a variety of different contacts for connecting to the outside world. The spatial light modulator involves the use of a liquid crystal layer which is confined between a pair of spaced plates. Conventionally, the requirements for packaging liquid crystal based devices and microprocessors have been considered to be substantially different.
Thus, there is a continuing need for ways to better integrate microprocessors and spatial light modulators to achieve processor-based systems with more compact display arrangements.
In accordance with one aspect, a packaged integrated circuit device includes a die having a processor and image processing circuitry formed thereon. A liquid crystal layer is positioned over the image processing circuitry. An interposer is bump bonded to the die. The interposer is arranged to allow light to reach the liquid crystal layer.
Other aspects are set forth in the accompanying detailed description and claims.